Telephone controlled lock release arrangement

Abstract

Circuitry is disclosed for the automatic dial-up of an apartment telephone from a lobby telephone to provide voice communication therebetween via a central switching office and for controlling the establishment of a switched signaling path through a switching network independent of the central office and then the unlocking of the lobby door over that switched path. The circuitry includes a trunk circuit for connecting the lobby telephone set to the central office and service circuits for detecting and processing call on/off-hook and ring signals as well as lobby door lock release signals from the called apartment. Distinctive tone bursts are applied by a service circuit through the switched path to notify the called apartment dweller of a lobby originated call.

What is claimed is: 
     
       1. A lobby-apartment communication and lobby door lock control system comprising: means for establishing a voice communication path from a lobby telephone over a communication line and a telephone central office to an apartment telephone;   lock control means, and   means responsive to a receipt of coded signals by said establishing means for providing a switched signaling path independent of said central office and between said apartment telephone and said control means; and   said control means comprising means responsive to a receipt of authorization signals from said apartment telephone via said switched signaling path for generating a control signal to effect an opening of a lobby door lock.   
     
     
       2. A system in accordance with claim 1 further comprising: means connectable to said switched signaling path for supplying over said last-mentioned path an alerting signal to said apartment telephone.   
     
     
       3. A system in accordance with claim 1 wherein said authorizing signals include coded multifrequency signals, and   said control means includes a multifrequency receiver responsive to a receipt of said coded multifrequency signals over said switched signaling path from said apartment telephone for controlling a generation of said control signal to effect said opening of said lobby door lock.   
     
     
       4. A system in accordance with claim 1 wherein said authorizing signals include coded dial pulse signals, and   said control means includes a detector responsive to a receipt of said coded dial pulse signals over said switched signaling path from said apartment telephone for controlling a generation of said control signal to effect said opening of said lobby door lock.   
     
     
       5. A system in accordance with claim 1 wherein said establishing means comprises a circuit having a first termination connectable to said lobby telephone, a second termination connectable to said communication line, and a third termination connected to said means providing said switched signaling path independent of said central office.   
     
     
       6. A system in accordance with claim 5 wherein said means providing said switched signaling path comprises a crosspoint switching network for furnishing said switched signaling path between said third termination and said apartment telephone.   
     
     
       7. A system in accordance with claim 1 wherein a multifrequency receiver is shared by said providing means and said lock control means for detecting multifrequency coded signals and multifrequency authorization signals. 
     
     
       8. A system in accordance with claim 1 wherein said establishing means is responsive to a receipt of prefix digits and directory digits identifying said apartment telephone for establishing said voice communication path, and said means providing a switched signalling path comprises   a state counter for counting each of said prefix digits to enable said voice communication path to said central office following a completion of the counting of said prefix digits and for enabling a transmission of said directory digits to said central office.   
     
     
       9. A system in accordance with claim 8 further comprising means for supplying an alerting signal through said switched signaling path to said apartment telephone and wherein said state counter is operable in response to a receipt of a prescribed number of said digits for extending the supplied alerting signal from said supplying means to said switched signaling path.   
     
     
       10. A system in accordance with claim 9 wherein said control means further comprises line state detector means connectable through said switched signaling path to said apartment telephone and responsive to idle-busy states of said apartment telephone for cooperating with said state counter to extend said supplied alerting signal from said supplying means to said apartment telephone via said switched signaling path prior to a completion of the receipt of said directory digits by said establishing means when said apartment telephone is busy and following a completion of the receipt of said directory digits by said establishing means when said apartment telephone is idle.   
     
     
       11. A system in accordance with claim 10 wherein said alerting signal supplying means includes: a tone generator, and   tone generator control means for enabling said tone generator to supply said tone in response to control signals from said line state detector means; and said line state detector means comprises   delay means for timing the duration of supervisory states of said apartment telephone to ensure that said control signals from said line state detector means are supplied to said tone control means in response to a detected supervisory state of prescribed duration.   
     
     
       12. A system in accordance with claim 11 wherein said delay means comprises: an on-hook off-hook delay circuit for sensing said idle-busy states of said apartment telephone; and   a ring delay circuit for recognizing incoming call ringing to said apartment telephone over said switched signaling path from said central office.   
     
     
       13. A system in accordance with claim 12 wherein said control signal generating means comprises logic means activated by said line state detector means in response to a receipt thereby of dial pulse authorization signals from said apartment telephone via said switching signaling path for funishing said control signal to effect an opening of said lobby door lock, and said control means includes   a multifrequency receiver responsive to a receipt of multifrequency authorization signals from said apartment telephone via said switched signaling path for activating said logic means to generate said control signal for effecting an opening of said lobby door lock.   
     
     
       14. A system in accordance with claim 13 wherein said logic means includes means for checking the validity of said authorization signals prior to generating said control signal to effect an opening of said lobby door.   
     
     
       15. A system in accordance with claim 14 wherein said logic means further comprises means for controlling said establishing means for temporarily disconnecting said lobby telephone from said voice communication path during the checking of said authorization signals by said checking means for precluding said lobby telephone from transmitting undesired authorization signals via said central office to said switched signaling path.   
     
     
       16. A system in accordance with claim 15 wherein said authorization signals comprise a prescribed digit number and said checking means includes: means connected to said line state detector means for counting the dial pulse authorization signals to determine a receipt of said prescribed digit number, and including   means responsive to a receipt of one dial pulse of said authorization signals for actuating said means for controlling said establishing means for temporarily disconnecting said lobby phone from said voice communication path.   
     
     
       17. A system in accordance with claim 16 wherein said checking means further includes: means responsive to an initial receipt of said multifrequency authorization signals comprising said prescribed digit number for actuating said means for controlling said establishing means for temporarily disconnecting said lobby telephone from said voice path connection, and   means responsive during the disconnection of said lobby telephone from said voice path connection to a continued receipt of said multifrequency authorization signals comprising said prescribed digit number for delaying the generation of said control signal to effect an opening of said lobby door lock to verify that the receipt of said multifrequency authorization signals is from said apartment telephone.   
     
     
       18. A system in accordance with claim 8 further comprising: means activated by said establishing means for timing the duration that a lobby telephone is connected over said communication line and said central office to said apartment telephone; and   means for automatically disconnecting said lobby telephone from said voice communication path to terminate lobby-apartment communication.   
     
     
       19. A system in accordance with claim 18 wherein said establishing means includes: a trunk circuit for interconnecting said lobby telephone and said communication line, and   said disconnecting means is effective to control said trunk circuit to disconnect said lobby telephone from said communication line when said lobby telephone is connected to said communication line for longer than said prescribed duration.   
     
     
       20. A system in accordance with claim 19 wherein said trunk circuit comprises: means including a unidirectional amplifier for connecting a dial tone from said telephone central office to said communication line to said lobby telephone prior to a transmission of said coded signals from said lobby telephone; and   switch means controlled by said state counter following a receipt of said prefix digits for establishing a bidirectional transmission from said lobby telephone to said communication line.   
     
     
       21. A system in accordance with claim 20 wherein said switch means is controlled by said logic means to temporarily disconnect said lobby telephone from said bidirectional path during a receipt of said authorization signals. 
     
     
       22. A system for controlling communication and signaling between a plurality of lobbies and a plurality of apartments comprising: means activatable for establishing a voice communication path from any one of said lobbies over a communication line and a central office to any one of said apartments;   a preference circuit connectable to each of said lobbies for providing an ordered preference to enable service request signals from said lobbies to effect an activation of said establishing means;   logic means;   means responsive to a receipt of coded signals from said estblishing means for providing a switched communication path independent of said central office and between said one of said apartments and said logic means; and   said logic means comprising means responsive to a receipt of authorization signals from said one of said apartments via said switched signaling path for generating a control signal to effect an opening of a door lock for a preferred requesting one of said lobbies.   
     
     
       23. A circuit for controlling a lock mechanism comprising: circuit means having a first termination connectable to a first communication station and a second termination connectable through a telephone switching office to establish a call connection between said first station and a selected one of a plurality of other communication stations;   logic means connectable to said lock mechanism and actuatable in response to a prescribed release signal from said selected one of said other stations for generating a signal to effect an actuation of said mechanism; and   switching network means connected to said circuit means and operated in response to path selection signals sent thereto from said first station for establishing a switched signaling path independent of said switching office and via which said prescribed release signal is transmitted between said selected one of said other stations and said logic means.   
     
     
       24. A circuit in accordance with claim 23 further comprising service circuitry coupled between said signaling path and said logic means for detecting said prescribed release signal generated from said selected one of said other stations to actuate said logic means.   
     
     
       25. A circuit in accordance with claim 24 wherein said prescribed release signal is a prescribed digit and wherein said service circuitry comprises a first service circuit for monitoring voltage levels on said signaling path to said selected one of said other stations to determine the call state thereof and responsive to a sensing of a plurality of alternating voltage level dial pulses dialed from said selected one of said other stations to actuate said logic means when the number of said plurality of dial pulses is equal to said prescribed digit.   
     
     
       26. A circuit in accordance with claim 25 further comprising means coupled to said first service circuit and to said switched signaling path for generating a tone thereover to said selected one of said other stations in response to a sensing of particular call states of said other stations by said first service circuit to provide an alerting signal to said selected one of said other stations to indicate a call origination from said first station.   
     
     
       27. A circuit in accordance with claim 26 wherein said service circuitry further comprises a second service circuit coupled between said switched signaling path and said logic means for receiving multifrequency tones dialed over said switched signaling path from said selected one of said other stations to actuate said logic means when a received multifrequency tone represents said prescribed digit.   
     
     
       28. A circuit in accordance with claim 27 wherein said path selection signals are multifrequency tone digits, and said second service circuit is further coupled between said circuit means and said switching network means for detecting said path selection signals sent to said circuit means to operate said switching network means to establish said switched signaling path.   
     
     
       29. A circuit in accordance with claim 28 wherein said call connection is established under control of said circuit means in response to multifrequency tone digits sent thereto from said first station, said circuit further comprising: means coupled to said second service circuit for counting said path selection digits and said last-mentioned tone digits detected thereat and the interdigital periods therebetween; and   means operative during counting of said switched signaling path selection digits by said last-mentioned means and for disabling a transmission path across said circuit means between said first termination and said second termination thereof to prevent said path selection signals from being sent to said telephone switching office and being responsive to a completion of counting of said selection digits by said counting means for restoring said transmission path.   
     
     
       30. A circuit in accordance with claim 29 further comprising means coupled to said tone generating means and responsive to said first service circuit sensing an off-hook voltage level at said selected one of said other stations and to a counting of said tone digits at said counting means for controlling said tone applying means to effect a periodic application of tone bursts to said selected one of said other stations over said switched signaling path.   
     
     
       31. A circuit in accordance with claim 30 wherein said logic means further comprises: means coupled to said service circuitry for recognizing said prescribed digit; and   means coupled to said lock mechanism for delaying for a predetermined interval the generation of said signal effecting said actuation of said lock mechanism after recognition of said designated digit by said last-mentioned means to prevent receipt of a higher-valued digit at said service circuitry from effecting an actuation of said lock mechanism.   
     
     
       32. A circuit in accordance with claim 31 further comprising: means included in said recognizing means and coupled to said first service circuit for counting said dial pulses sensed thereat; and   means operated during said counting by said last-mentioned means and during said predetermined interval for temporarily disabling said transmission path in said trunk circuit means between said first termination and said second termination thereof to prevent generation of a simulated release signal from said first station.   
     
     
       33. An arrangement for controlling a door lock mechanism in the lobby of an apartment building wherein said building includes a lobby telephone and a plurality of apartment telephones having lines connectable to a telephone central office, comprising: circuit means connectable between said lobby telephone and the central office for controlling the establishment of a voice path connection switched via said office to a selected one of said apartment telephones;   receiving means coupled to said circuit means for detecting coded signals generated from any one of said telephones;   switching means connectable to said apartment telephones for selectively establishing a switched signaling path separate and independent of said office between said receiving means and said one of said apartment telephones in response to a detection by said receiving means of coded signals generated from said lobby telephone; and   logic means responsive to a receipt in said receiving means of a predetermined digit generated from said selected one of said apartment telephones over said switched path for generating a control signal to effect a release of said door lock mechanism.   
     
     
       34. The arrangement in accordance with claim 33 further comprising: digit counting means connected to said receiving means for indicating a completion of generation of said coded signals from said lobby telephone;   means coupled to said switched signaling path and responsive to voltage changes generated on said path by said selected one of said apartment telephones for detecting the state thereof; and   means coupled to said switched signaling path and controlled by said digit counting means and said state detecting means for generating audible bursts of tone on said path for said selected one of said apartment telephones to alert a user thereof of a call attempt from said lobby telephone.   
     
     
       35. The arrangement in accordance with claim 33 wherein said logic means further comprises: means responsive to a detection of said predetermined digit by said receiving means for establishing a delay interval; and   means coupled to said circuit means and operated only during said delay interval for disabling said voice path connection to impede simulation of said predetermined digit at said lobby telephone.   
     
     
       36. An arrangement for sending a lock mechanism release signal comprising: a lock controlled access location equipped with a lock mechanism and a telephone set for requesting release of said lock mechanism;   a plurality of authorizing telephone sets; and   a telephone central office for establishing a switched voice path connection between said requesting set and one of said authorizing sets in response to a sending of telephone directory digits of said one of said authorizing sets from said requesting set;   service circuit means for detecting signaling states of said authorizing sets;   switching network means responsive to a sending from said requesting telephone set of a predetermined set of prefix digits assigned to said one of said authorizing sets for selectively establishing a switched signaling path separate and independent of said central office and over which a predetermined lock release signal generated from said one of said authorizing sets is sent to said service circuit means; and   logic circuit means coupled to said service circuit means and to said lock mechanism for recognizing said predetermined lock release signal detected by said service circuit means to effect an opening of said lock mechanism.   
     
     
       37. The arrangement of claim 36 further comprising: means coupled to said switched signaling path and responsive to a detection by said service circuit means of particular ones of said signaling states and of supervisory states of said one of said authorizing sets for transmitting a signal thereto via said signaling path connection to alert a user of said one of said authorizing sets that said requesting set is attempting to complete a call.   
     
     
       38. The arrangement in accordance with claim 37 further comprising: repertoire dialer means included in said requesting telephone set and having prerecorded in memory prefix digits and directory digits assigned to each of said authorizing sets for automatically outpulsing said prefix digits and said directory digits of said one of said authorizing sets in response to a depressing of a one of a plurality of pushbuttons corresponding to said one of said authorizing sets, and   trunk circuit means connected in a transmission path between said requesting set and said central office for controlling the establishment of said voice path connection and effective during the outpulsing of said prefix digits from said requesting set to disable said transmission path to prevent said prefix digits from reaching said telephone central office; and said service means comprising   a digit receiver connected to said trunk circuit means and to said switching network means for detecting said prefix digits and said directory digits received at said trunk circuit means and responsive to a detection of said prefix digits to transmit signaling path selection signals to said switching network means to thereby effect an establishment of said switched signaling path; and   means connected to said digit receiver for counting said prefix digits and said directory digits detected at said digit receiver and responsive to a completion of counting of said prefix digits to signal said trunk circuit means to restore said transmission path to enable said directory digits to be outpulsed to said central office.   
     
     
       39. The arrangement in accordance with claim 38 wherein said lock release signal is a digit comprised of a prescribed number of dial pulses generated from said authorizing set and said logic circuit means comprises: means connected to said service circuit means for counting dial pulses detected thereat to identify said lock release signal digit when said prescribed number has been reached; and   means responsive to said service circuit means reaching said prescribed number of dial pulses for establishing a delay interval to effect said opening of said lock mechanism upon expiration of said interval.   
     
     
       40. The arrangement in accordance with claim 39 wherein said logic circuit means further comprises means operated in response to said dial pulse counting means achieving a count of two and maintained operated during said delay interval for signaling said trunk circuit means to disabled said transmission path to prevent unauthorized lock release by the sending of said lock release signal digit from said requesting set.